#include <ArduinoJson.h>
#include <SPI.h>
#include <SD.h>

const int potPin = 34;
const int ledPin = 25;
const int buzzerPin = 26;
const int chipSelect = 5;

unsigned long tempOver35StartTime = 0;
bool isTempOver35 = false;
bool alertActive = false;

File dataFile;

void setup() {
  Serial.begin(115200);
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(chipSelect, OUTPUT);
  
  if (!SD.begin(chipSelect)) {
    Serial.println("Initialization of SD card failed!");
    return;
  }
  Serial.println("Initialization of SD card successful!");
}

void loop() {
  float temperature = readTemperature();
  Serial.print("Simulated Temperature: ");
  Serial.println(temperature);
  
  if (temperature > 35) {
    if (!isTempOver35) {
      tempOver35StartTime = millis();
      isTempOver35 = true;
    } else if (millis() - tempOver35StartTime > 10000 && !alertActive) {
      activateAlert();
      alertActive = true;
      logData(temperature, true);
    }
  } else {
    isTempOver35 = false;
    if (alertActive) {
      delay(5000);
      deactivateAlert();
      alertActive = false;
      logData(temperature, false);
    }
  }
  delay(1000);
}

float readTemperature() {
  int sensorValue = analogRead(potPin);
  float voltage = sensorValue * (3.3 / 4095.0); 
  float temperature = voltage * 100.0;
  return temperature;
}

void activateAlert() {
  digitalWrite(ledPin, HIGH);
  digitalWrite(buzzerPin, HIGH);
  Serial.println("Alert activated: Temperature over 35°C");
}

void deactivateAlert() {
  digitalWrite(ledPin, LOW);
  digitalWrite(buzzerPin, LOW);
  Serial.println("Alert deactivated: Temperature below 35°C");
}

void logData(float temperature, bool alert) {
  if (SD.exists("temperature_log.json")) {
    dataFile = SD.open("temperature_log.json", FILE_WRITE);
  } else {
    dataFile = SD.open("temperature_log.json", FILE_WRITE);
    dataFile.println("[");
  }
  
  if (dataFile) {
    DynamicJsonDocument doc(256);
    doc["timestamp"] = millis();
    doc["temperature"] = temperature;
    doc["alert"] = alert;

    if (SD.exists("temperature_log.json")) {
      dataFile.seek(dataFile.size() - 1);
      dataFile.println(",");
    }
    
    serializeJson(doc, dataFile);
    dataFile.println("]");
    dataFile.close();
  } else {
    Serial.println("Error opening file for writing");
  }

}